The present disclosure relates to a reactor inlet, and, more particularly, to a reactor inlet for a fuel reforming system that provides a homogeneous mixture of fluids.
Several strategies are known in the art of fuel processing to improve fuel economy and comply with the Environmental Protection Agency (EPA) exhaust emission standards for a spark ignition engine. One such strategy is fuel reforming such as on-board steam reforming, autothermal reforming and partial oxidation reforming of gasoline. For example, gasoline partial oxidation (POx) reforming strategies involve mixing fuel, air and/or exhaust gas, and partially oxidizing the fuel with a catalyst to produce two primary products, hydrogen and carbon monoxide. The carbon monoxide may then be used as a fuel in a spark ignition engine, for example, whereas the hydrogen product may be used to run the engine with excess diluent either very lean with excess air or at stoichiometric air to fuel ratios with excess exhaust gas recirculation (EGR). Either scheme may result in increased fuel economy and lower oxides of nitrogen (NOx) emissions.
Hydrogen is highly flammable and produces lower engine-out emissions, such as undesirable oxides of nitrogen (NOx). A fuel reforming system generates H2 from hydrocarbon fuels such as natural gas and gasoline, and alcohols such as methanol and ethanol.
Fuel reforming processes include steam reforming such as catalytic steam reforming, partial oxidation, and autothermal reforming. Steam reforming is an endothermic reaction wherein fuel is mixed with steam in the presence of a metal catalyst to produce H2 and CO. Partial oxidation, an exothermic reaction, is used to process methane and higher hydrocarbons, as inCH4+½O2→CO+2H2 which requires minimal external heat energy in a thermally efficient system. Autothermal reforming combines the endothermic steam reforming with the exothermic partial oxidation reaction, thereby balancing the heat flow into and out of the reactor.
However, in order to produce as much hydrogen (H2) and carbon monoxide (CO) as possible, a good homogeneous mixture of the reactants is desired as well as a means to evenly distribute that mixture over a catalyst. Prior art processes and fuel reforming systems often fail to provide a homogeneous mixture of reactants. A typical fuel reactor may rely on turbulence and/or flow dynamics to mix the reactants. Other known reactors include an inlet having a porous foam such as a ceramic foam to provide a mixture of reactants. As shown in FIG. 1, for example, a typical ceramic foam inlet is shown generally as 5 may comprise a cone shaped insert of varying cone angles and materials for the passage of fluid. However, ceramic foam often has non-uniform porosity and/or blockage of pore space. The ceramic foam inlet 5 fails to provide a homogeneous mixture of the reactants. Accordingly, there remains a need in the art for improved fuel reformer systems and processes for providing a homogeneous reactant mixture and increase thermal efficiencies associated with the homogeneous mixture.